One reason i could say is the absence of middle class in islam. middle class is a strong part of the society which does not hesitate to speak its mind. The lower class due to fear of being marginalized often follow the dictates of the upper class. the upper class understands that for it to remain powerful they need to exploit the lower class (which means keeping them deprived rather than working towards their upliftment). End result is religion becomes an important tool for the upper class to manipulate the lower class. An example would be Sharia law for banking which states that its not lawful to pay or collect interest (there are certain loopholes though). This makes it impossible for the havenots to rise. In india we dont follow these laws. But i know many muslims in india donot want to borrow money from banks as they feel paying interest would be against the Sharia law.
